IT Questions and Answers :)

Friday, February 28, 2020

What is the name of the numeric value used to identify a memory cell?

What is the name of the numeric value used to identify a memory cell?

  • Boolean operation
  • Hexadecimal notation
  • Bit
  • Address

What is the name of the numeric value used to identify a memory cell?

EXPLANATION

A digital computer's memory, more specifically main memory, consists of many memory locations, each having a physical address, a code, which the CPU (or other device) can use to access it. Generally only system software, i.e. the BIOS, operating systems, and some specialized utility programs (e.g., memory testers),
address physical memory using machine code operands or processor registers, instructing the CPU to direct a hardware device, called the memory controller, to use the memory bus or system bus, or separate control, address and data busses, to execute the program's commands. The memory controllers' bus consists of a number of parallel lines, each represented by a binary digit (bit). The width of the bus, and thus the number of addressable storage units, and the number of bits in each unit, varies among computers.

SOURCE

https://en.wikipedia.org/wiki/Memory_address
 
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Monday, August 19, 2019

On a desktop or laptop what does a G3 power state refer to?

On a desktop or laptop what does a G3 power state refer to?

  • Mechanical Off
  • BIOS Update In Progress
  • Low Power Mode For Battery Performance
  • Working Off 

 
On a desktop or laptop what does a G3 power state refer to?

EXPLANATION

"Mechanical Off" - G3 - The system is completely off and consumes no power. The system returns to the working state only after a full reboot.
Can be performed by holding down Shift when clicking Shutdown.

SOURCE

https://docs.microsoft.com/en-us/windows/desktop/power/system-power-states
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Monday, July 1, 2019

Which operating system would not be able to boot if it were installed on an NVMe drive?

Which operating system would not be able to boot if it were installed on an NVMe drive?

  • Windows XP
  • Windows 7
  • Windows 8.1
  • Windows 10 

 
Which operating system would not be able to boot if it were installed on an NVMe drive?

EXPLANATION

Windows XP is too old, and there are no NVMe drivers available for it. Newer motherboards (Skylake and newer) that can boot from NVMe also will not support Windows XP.

SOURCE

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Tuesday, April 30, 2019

What is/was the purpose for using a Dynamic Disk Overlay?

What is/was the purpose for using a Dynamic Disk Overlay?

  • Software to increase existing disk drives speed.
  • Software to hide a disk drive from hackers.
  • A dust cap for the disk drive to be used when cleaning the system.
  • Software technique to extend a system BIOS that does not support logical block addressing (LBA). 

 
What is/was the purpose for using a Dynamic Disk Overlay?

EXPLANATION


Dynamic drive overlay (DDO, also referred to as: software translation driver) is a software technique to extend a system BIOS that does not support logical block addressing (LBA) to access drives larger than 504 MiB. The technology was continued with similar types of problems up to the LBA-48 extension.

The most widespread vendor for such an extension is the company Ontrack which is licensing its DDO component to several of the major hard disk vendors for integration into their management tools and into their products.
The application of a Dynamic Drive Overlay (DDO), as licensed to Samsung Corporation for example, by Kroll Ontrack's version in their Disk Manager program is for the installation of various hard drives (Ultra/Super IDE/Parallel ATA) in computers that have older BIOS chips that do not recognize hard disk drives larger than 137.4 Gigabytes.[1] The interface is a software program that is loaded at start-up by the computer and augments the BIOS code, thus allowing the system to recognize and read areas of the hard disk drive that normally would not be accessible by the older BIOS.

This technique overrides some of the motherboard BIOS' hard disk controller driver in RAM. To allow access to the full size of any hard disk the software must be loaded before other programs try to access the upper parts of a disk with a critical size. To ensure that this extension gets loaded early most often the boot disk's master boot record is modified and the software installed at the beginning of the disk.

SOURCE

https://en.wikipedia.org/wiki/Dynamic_drive_overlay
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Monday, April 8, 2019

What is the minimum number of passes in a DOD-Level Data Wipe?

What is the minimum number of passes in a DOD-Level Data Wipe?

  • Three
  • Five
  • Six
  • Two 

EXPLANATION

How Does a DOD-Level Data Wipe Work? Three Pass Overwrite
A three pass overwrite means that the data is overwritten with a set of characters three times. There is a verification pass as well to check that all the data on the drive has been overwritten.
There is a standard process for the three pass overwrite: a single pass with a “0” character, followed by a single pass with a “1” character, and a final pass with a random character.
Seven Pass Overwrite
Like the three pass overwrite, the seven pass pattern overwrites the data many times with a specific pattern of characters.
The standard seven pass process is: a “0” character pass, a “1” character pass, random character pass, a second random character pass, a “0” character pass, a “1” character pass, and a random character pass before the final verification pass.

SOURCE

http://www.reliant-technology.com/storage_blog/dod-data-wipe-standards/
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Tuesday, March 26, 2019

What is the primary difference between LED and an LCD monitor?

What is the primary difference between LED and an LCD monitor?

  • Doesn't last as long as plasma displays
  • screen size
  • Backlighting source
  • price 

 
What is the primary difference between LED and an LCD monitor?

EXPLANATION

LCD
LCD is the abbreviation of Liquid Crystal display. There are two layers of glass in this technology that are joined together with liquid crystals in between. These crystals help pass or block the light. However, crystals do not produce any light and it comes through fluorescent lamps (CCFL) situated at the back of the screen.
LED
The technology in LED TV’s is much the same with the difference being the source of light at the back of the screen. Whereas it is CCFL in the case of LCD, there is Light emitting Diodes (LED’s) in the case of LED TV’s.
http://www.differencebetween.com/difference-between-lcd-and-vs-led-monitor/
http://www.diffen.com/difference/LCD_TV_vs_LED_TV

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Thursday, March 21, 2019

What does a "Framebuffer" do?

What does a "Framebuffer" do?

  • It allows for smoother frame rates whilst in an active remote session by using a portion of RAM
  • It stores an in-memory bitmap for conversion to a video signal that can be displayed
  • It renders bitmap images in a dot matrix data format, displaying a rectangular grid of pixels
  • It stores and displays a graphical image as a rectangular array of pixel colour values. 

What does a "Framebuffer" do?

EXPLANATION

A framebuffer (frame buffer, or sometimes framestore) is a portion of RAM containing a bitmap that drives a video display.
It is a memory buffer containing a complete frame of data. Modern video cards contain framebuffer circuitry in their cores.

SOURCE

https://en.wikipedia.org/wiki/Framebuffer
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Thursday, March 14, 2019

What is the unique identifier for network hardware called?

What is the unique identifier for network hardware called?

  • Gettysburg address
  • MAC address
  • IP address
  • Network address 

 
What is the unique identifier for network hardware called?

EXPLANATION

A media access control (MAC) address is a unique identifier associated with network hardware for communicating on the physical network.
A media access control address of a device is a unique identifier assigned to a network interface controller for communications at the data link layer of a network segment. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet and Wi-Fi. In this context, MAC addresses are used in the medium access control protocol sublayer.
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Friday, March 8, 2019

CPUs have a NX flag/bit to segregate areas of memory for process instruction or data. What does NX stand for?

CPUs have a NX flag/bit to segregate areas of memory for process instruction or data. What does NX stand for?

  • NineX
  • Non-Existent
  • No-Execute
  • Near-Exact 
CPUs have a NX flag/bit to segregate areas of memory for process instruction or data. What does NX stand for?

EXPLANATION


The NX bit (no-execute) is a technology used in CPUs to segregate areas of memory for use by either storage of processor instructions (code) or for storage of data, a feature normally only found in Harvard architecture processors. However, the NX bit is being increasingly used in conventional von Neumann architecture processors, for security reasons.
An operating system with support for the NX bit may mark certain areas of memory as non-executable. The processor will then refuse to execute any code residing in these areas of memory. The general technique, known as executable space protection, is used to prevent certain types of malicious software from taking over computers by inserting their code into another program's data storage area and running their own code from within this section; one class of such attacks is known as the buffer overflow attack.
Intel markets the feature as the XD bit (execute disable). Advanced Micro Devices (AMD) uses the marketing term Enhanced Virus Protection (EVP). The ARM architecture refers to the feature, which was introduced in ARMv6, as XN (execute never).[1] The term NX bit itself is sometimes used to describe similar technologies in other processors.

SOURCE

https://en.wikipedia.org/wiki/NX_bit
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Thursday, February 28, 2019

On a UNIX or MacOS system, what is the term for what, on the Windows OS, is commonly known as the Blue Screen of Death (BSOD)?

On a UNIX or MacOS system, what is the term for what, on the Windows OS, is commonly known as the Blue Screen of Death (BSOD)?

  • Integrity Check Failure
  • Kernel Lock
  • Kernel Panic
  • Buffer Overflow 

 
On a UNIX or MacOS system, what is the term for what, on the Windows OS, is commonly known as the Blue Screen of Death (BSOD)?

EXPLANATION

Since the kernel handles the most basic functions of a computer, if it crashes it can take down the entire computer. This undesirable event is called a "kernel panic"
on m=MacOS and Unix systems. It is similar to the blue screen of death in Windows.

SOURCE

https://techterms.com/definition/kernel
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Tuesday, January 29, 2019

What is the "Power Good Signal", according to the ATX specification?

What is the "Power Good Signal", according to the ATX specification?

  • -5 Volt current the motherboard generates to indicate it's functioning.
  • LED power light on the computer indicating proper function
  • Means that the power supplied to the computer power supply is ample
  • +5 volt signal generated in the power supply that is supplied to the motherboard 

What is the "Power Good Signal", according to the ATX specification?

EXPLANATION

The Power Good signal (sometimes called Power_OK or PWR_OK) is a +5 V (nominal) active high signal (with a variation from +2.4 V through +6.0 V generally being considered acceptable) that is supplied to the motherboard when the power supply has passed its internal
self-tests and the output voltages have stabilized. This typically takes place anywhere from 100 ms to 500 ms (0.1–0.5 seconds) after you turn on the power supply switch. The power supply then sends the Power_Good signal to the motherboard, where the processor timer chip that controls the reset line to the processor receives it.

SOURCE

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Tuesday, December 4, 2018

What is the largest partition size supported by native DOS running FAT16?

What is the largest partition size supported by native DOS running FAT16?

  • 3GB
  • 2GB
  • 1GB
  • 512MB 
What is the largest partition size supported by native DOS running FAT16?

EXPLANATION

Due to the mathematical limitations of FAT16, without an overlay file or special driver the largest partition size is 2GB.The limit on partition size was dictated by the 8-bit signed count of
sectors per cluster, which originally had a maximum power-of-two value of 64. With the standard hard disk sector size of 512 bytes, this gives a maximum of 32 KiB cluster size, thereby fixing the "definitive" limit for the FAT16 partition size at 2 GiB for sector size 512.

SOURCE

https://en.wikipedia.org/wiki/File_Allocation_Table

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Wednesday, November 7, 2018

Which of the following is the main purpose of a parked CPU core?

Which of the following is the main purpose of a parked CPU core?

  • Saves Power
  • Increase performance of applications
  • Reserves CPU core for specific application process
  • To prolong the lifespan of the CPU 
 Which of the following is the main purpose of a parked CPU core?

EXPLANATION

This process essentially puts your CPU cores in a sleep state, and wakes them up when an application depends on higher core usage. Majority of the time this is left enabled unless your a power user or a gamer. It can increase performance slightly for those situations. On some processors, this option cannot be disabled.


SOURCE

https://ttcshelbyville.wordpress.com/2013/12/29/what-is-core-parking-and-should-you-adjust-it/

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Thursday, October 11, 2018

What is the maximum number of devices that you can connect to a single USB 2.x controller?

What is the maximum number of devices that you can connect to a single USB 2.x controller?

  • 255
  • 31
  • 63
  • 127

What is the maximum number of devices that you can connect to a single USB 2.x controller?

EXPLANATION

Technically, a USB network is capable of supporting 128 nodes, though the USB controller itself is also a node.
In addition, any USB hubs, self-powered or bus-powered, count as additional nodes and reduce the number of nodes you can connect to the controller.
https://en.wikipedia.org/wiki/USB_hub#Physical_layout
 
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Thursday, August 30, 2018

Which of these is NOT a card bus type?

Which of these is NOT a card bus type?

  • SOX
  • ISA
  • AGP
  • PCI 

 
Which of these is NOT a card bus type?

EXPLANATION

CardBus is the trade name for an advanced PC Card specification. The technology is used primarily in notebook and portable computers and fits in a slot like a conventional PC card. ISA, AGP, and PCI are all card bus types.
SOX is a common abbreviation for the Sarbanes-Oxley Act, a US Federal law governing publicly traded companies.

 


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Thursday, August 16, 2018

What is the primary difference between LED and an LCD monitor?

What is the primary difference between LED and an LCD monitor?

  • price
  • Backlighting source
  • Doesn't last as long as plasma displays
  • screen size 

 
What is the primary difference between LED and an LCD monitor?

EXPLANATION

LCD
LCD is the abbreviation of Liquid Crystal display. There are two layers of glass in this technology that are joined together with liquid crystals in between. These crystals help pass or block the light. However, crystals do not produce any light and it comes through fluorescent lamps (CCFL) situated at the back of the screen.
LED
The technology in LED TV’s is much the same with the difference being the source of light at the back of the screen. Whereas it is CCFL in the case of LCD, there is Light emitting Diodes (LED’s) in the case of LED TV’s.
http://www.differencebetween.com/difference-between-lcd-and-vs-led-monitor/
http://www.diffen.com/difference/LCD_TV_vs_LED_TV
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Thursday, August 9, 2018

Which of the following retains the information it's storing when the system power is turned off?

Which of the following retains the information it's storing when the system power is turned off?

  • ROM
  • RAM
  • GPU
  • CPU 

 
Which of the following retains the information it's storing when the system power is turned off?

EXPLANATION

Read only memory (ROM) is nonvolatile, meaning that turning off the computer doesn't erase it. 

Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM can only be modified slowly, with difficulty, or not at all, so it is mainly used to store firmware (software that is closely tied to specific hardware, and unlikely to need frequent updates) or application software in plug-in cartridges.
Strictly, read-only memory refers to memory that is hard-wired, such as diode matrix and the later mask ROM (MROM), which cannot be changed after manufacture. Although discrete circuits can be altered in principle, integrated circuits (ICs) cannot, and are useless if the data is bad or requires an update. That such memory can never be changed is a disadvantage in many applications, as bugs and security issues cannot be fixed, and new features cannot be added.


More recently, ROM has come to include memory that is read-only in normal operation, but can still be reprogrammed in some way. Erasable programmable read-only memory (EPROM) and electrically erasable programmable read-only memory (EEPROM) can be erased and re-programmed, but usually this can only be done at relatively slow speeds, may require special equipment to achieve, and is typically only possible a certain number of times

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Friday, July 13, 2018

A standard rectangular male USB connector (for example, the connector on most mouse/ cables) is what type of connector?

A standard rectangular male USB connector (for example, the connector on most mouse/ cables) is what type of connector?

  • USB Type C
  • USB Type B
  • Micro USB 3.0
  • USB Type A 

A standard rectangular male USB connector (for example, the connector on most mouse/ cables) is what type of connector?

EXPLANATION

standard male USB
 connector for peripheral devices is known as a USB Type A Male connector.  Type B is the more squared or house shaped connector that is commonly used on printers or scanners to connect to a computer
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Monday, July 9, 2018

What is the maximum number of USB devices a host controller can handle?

What is the maximum number of USB devices a host controller can handle?

  • 128
  • 155
  • 64
  • 127 

 
What is the maximum number of USB devices a host controller can handle?

EXPLANATION

At 7 bits long, a single USB Host Controller can allow up to 127 (2^7 – 1 Host Controller) connected devices.

USB hubs can be cascaded up to seven times, the maximum number of user devices is reduced by number of hubs. So, with 19 hubs attached, the maximum number of available devices is reduced 127 − 19 = 108.

SOURCE

https://en.wikipedia.org/wiki/USB_hub (Physical Layout section)
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Wednesday, May 23, 2018

In a computer device, which of the following types of memory has the fastest access time?

In a computer device, which of the following types of memory has the fastest access time?

  • PCIe based SSD memory
  • RAM
  • CPU register
  • CPU cache 

 
In a computer device, which of the following types of memory has the fastest access time?

EXPLANATION

The faster the memory is the more expensive. Also the closer to the CPU is the lesser the latency would be. In this regard one can reasonably suggest which is the fastest memory only be looking by it size and location in the system.

The fastest memory block in a computer is the CPU register but it is also the smallest. It is followed by various levels of CPU cache. More info can be found here:
http://www.moreprocess.com/devices/computer-memory-hierarchy-internal-register-cache-ram-hard-disk-m...
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